Piledriver! portrays an epic struggle between 4 vikings trying to prove their strength to the village.
Backwards: One or more aspects of the game works the opposite as would normally be expected: maybe the controller is reversed (left is right, right is left), maybe you win lives every time you die, maybe it scrolls to the left and your character moonwalks.
More the Merrier: The game is a competitive or cooperative multiplayer "party game" (i.e., based on minigames, humor, 4+ players, audience engagement, etc.), meant for one screen or more.